Answer
Please see the work below.
Work Step by Step
(a) We know that the top has the greatest positive electric flux. The bottom has the greatest negative electric flux, while the ends and sides have zero flux.
(b) We can calculate the required electric flux as follows:
$\phi=EAcos\theta$
$\phi=6.00\times 10^3N/C\times 0.35\times 0.25m\times cos0^{\circ}=525Nm^2/C$
$\phi=EAcos\theta$
We plug in the known values to obtain:
$\phi=6.00\times 10^3N/C\times 0.35m\times 0.25m\times cos180^{\circ}$
$\phi=-525Nm^2/C$
$\phi=EAcos\theta$
$\phi=6.00\times 10^3N/C\times 0.25m\times 0.20m\times cos 90^{\circ}$
$\phi=0$
$\phi=EAcos\theta$
$\phi=6.00\times 10^3N/C\times 0.20m\times 0.35m\cos90^{\circ}$
$\phi=0$
